Leonardo da Vinci's Robot

A new Wired article
tells the interesting story of Leonardo da Vinci's 500 year-old design
for a three-wheeled, programmable robot. Originally described as a "car"
when the drawings were discovered, further research revealed the device
was more likely a robot. The robot was powered by springs and guided by
geared disks and cams. An earlier BBC article
also describes the model recently built from the original plans. Drawings,
exploded diagrams, and photos of a model can be found on the
Discovery Channel website. Their are also drawings of another,
humanoid robot Leonardo design but never built. The researcher
mentioned in the wired story, Mark Rosheim, is working on a book to be
called Leonardo's Lost Robots. His home page also has a more detailed
article about the reconstructed robot.